note: this doesn't really answer any of your questions but I just recently switched from a release iPhone 4 to a htc droid incredible on Saturday so I thought I'd give you my overall thoughts.
Build Quality: The iPhone 4 while having both a glass front and back just felt like the quality was just so much better. With my droid incredible, I purchased the white backplate and it already makes noises when I pick up the phone. I've only had the phone 4 days.
Hardware: Both phones are fast. Everyone complains about battery life on the droid incredible, it is pretty bad if you run a bunch of widgets that constantly update, I decided that I didn't want to run any widgets like that and I have no issues with battery life, it'll last me throughout the day with a lot of texting and web browsing. The battery on the droid incredible takes FOREVER (I'd say 4 hours to fully charge from low battery) to charge but the iPhone 4 charges really really fast and the battery lasts a long time.
Software: I have a lot of complaints with iOS when it comes to notifications and my only complaint I have with android is that I can't uninstall Verizon bloatware without rooting my phone.
With iOS text message notifications are annoying, you could be watching a youtube video, receive a text message and it completely stops the video. Or you could be trying to show somebody your phone and a text message pops up and there's no way to configure it to not pop up. I send and receive a lot of text messages so for somebody who doesn't this may not seem that bad, but for me it was really annoying. Also, in order to turn on bluetooth or wifi, you can't have a widget to make it easier, you have to open settings and press a few buttons to get to these settings. Sure it's not bad but if you're like me and like to turn things off when you're not using it, this was annoying. I love how on android I have widgets and can just press them off accordingly. And I won't even get started on the lock screen notifications either.
But, if you jailbreak an iPhone 4 all of my complaints go away however I'm not interested in doing that. If you do mess up your iPhone 4 it's so much easier to restore back to default (in my opinion of course)
Call Quality: Really no difference here to me. Both work great. Especially since you don't live in the US you won't have a problem like I did with AT&T.
Screen Quality: Coming from an iPhone 4 retina display I thought I would be extremely disappointed with the SLCD but I am not disappointed at all. The screen is actually better than I thought it was. The retina display is only slightly better to me.
Overall I'm happy with the switch from the iPhone 4 to the droid incredible, but I switched only for the verizon network. Having said that, if verizon had the iPhone 4 I wouldn't have made the switch in phones. But, in your latest post you're right, both phones are awesome and you can't really go wrong. Basically, the iPhone 4 is very simple and minimalistic. If you like to get creative or get bored of looking at the same theme/layout then I'd go with android. Apple support is also top notch so if you ever run into any issues they'll take care of you. Also, if you get the iPhone 4, I'd highly recommend picking up a Mobile Me subscription for "Find my iPhone" Good luck on your decision.